This invention relates to truck end gates.
One type of farm truck has a box type vehicle body for transporting grain or other fluent granular materials. It is usually provided with a hoist that can raise and lower the front end of the box to assist the unloading of grain through a central discharge opening in the rear wall of the box. The discharge of grain is controlled by a door, typically called an end gate, located in the central discharge opening.
In some end gates, a sliding door is guided by a pair of vertical tracks and is opened and closed by a lever system that transfers the rotational force of an opening handle into a vertical movement of the sliding plate. Variations of this basic system are shown in U.S. Pat. Nos. 2,258,203 and 2,635,688. These systems have several disadvantages, such as for example: (1) they are either too large for on-the-farm auger use or too small for rapid dumping at a large storage facility; and (2) they do not enable the load to be directed in its flow path nor to be balanced by drawing off the grain selectively from portions of the truck bed.
Some such grain trucks have an end gate opening that is wide such as between 30 inches to 36 inches. These wide end gates work well when unloading quickly into a large pit at a commercial grain company. For unloading on the farm, however, it is desirable at times to have a narrowed or directional flow from the end gate. Relatively small grain augers or conveyors are often used to elevate grain from the dump truck into storage areas and some means is usually used to direct the grain flow to the intake end of the auger.
In one prior art method of unloading grain on the farm, the grain is unloaded directly from the wide end gate. In this method, the truck is backed into axial alignment with the auger with the end gate opening squarely centered over the intake end of the auger. The grain is then unloaded directly into the auger intake.
This method of unloading has a disadvantage in that if the truck is off to the left or right an excess of grain flows one way or the other which can cause spillage and loss. Even if the truck is positioned correctly, a wide end gate opening causes the grain to spread out over a greater area than desired while unloading and results in the inefficient transfer of grain. The most efficient way to unload grain is to dump the grain into the intake of the auger in a narrow flow pattern.
One prior art solution to this problem uses shovels or other devices positioned at angles to force the grain to flow directly into the end of the auger. Also, boards or other objects may be jammed into the outer edges of the end gate opening in an attempt to block off part of the grain flow. These makeshift procedures have the disadvantage of being wasteful of time and being inefficient.
In some prior art equipment, for correcting the problems with end gates in unloading, metal chutes or hoppers such as those shown in U.S. Pat. Nos. 2,670,108; 2,678,121 and 3,090,527 are attached below the end gate opening and confine the grain flow toward the center.
This type of equipment has several disadvantages such as: (1) the chutes can make contact with the intake end of the auger when the box is tilted up and damage the auger flighting or the chute itself, thus limiting the height to which the grain box can be raised and the effectiveness of the dumping process; and (2) because the chutes are designed to restrict grain flow, they slow down the unloading process at commercial grain companies unless removed.
Another common method of confining grain flow is to provide a small hole in the center of the wide single gate and to attach a small sliding plate and track assembly to the outside surface of the gate to control flow from the smaller opening. This type of end gate is disclosed in U.S. Pat. No. 4,320,860. These small trap doors have a disadvantage of being hand-operated and tending to jam easily. They do not always provide the volume of grain flow desired because there is a limit to how big the opening can be made without weakening the structural strength of the larger sliding plate.
Some grain bodies are manufactured with an end gate that is fairly narrow in width. This can be an advantage when unloading into an auger but does not provide directional control. Smaller end gates can also be slow when dumping large loads at commercial grain companies. One such end gate is disclosed in U.S. Pat. No. 2,763,901.
There are several prior art end gates that provide directional control of grain flow from a central opening. Some such end gates have attachments that extend outwardly to direct the outward flow. Two such end gates are shown in U.S. Pat. Nos. 2,772,764 and 4,320,860. These end gates have disadvantages in that: (1) they do not permit leveling of a load that is initially unbalanced because the flow still originates from the center of the rear panel; and (2) they are subject to damage because of the extensions.
Segmented end gates are known for use with spreader boxes on gravel trucks. These end gates can level loads. Some such segmented end gates are disclosed in U.S. Pat. Nos. 2,258,842 and 2,850,216. This type of segmented end gate has the disadvantage of being complicated to use, expensive to manufacture and not suited for grain delivery.